Octamethylcyclotetrasiloxane (D4)

Octamethylcyclotetrasiloxane (D4)
SMILES
C[Si]1(O[Si](O[Si](O[Si](O1)(C)C)(C)C)(C)C)C
CAS number
556-67-2
Formula
C8 H24 O4 Si4
Molecular weight
296.62g/mol
Melting point
17  tM/°C reference 1
Entropy of fusion
not specified  ΔfusS/J K-1 mol-1

Vapor pressure

t/°C PS/Pa PL/Pa log (PL/Pa) method and notes reference
25 158 140 2.15 EPI Suite estimation
25 81.3 1.91 COSMOtherm calculation 2
25 209 2.32 SPARC estimation 2
25 224 2.35 Mazzoni et al. 2
25 162 2.21 Ahmed et al. 2
25 126 2.1 Lei et al. 2

Water solubility

t/°C SWS/mol m-3 SWL/mol m-3 log (SWL/mol m-3) method and notes reference
25 8.13E-4 -3.09 COSMOtherm calculation 2
25 5.37E-3 -2.27 SPARC estimation 2
25 5.75E-4 -3.24 WATERNT (EPI Suite) 2
25 2.04E-4 -3.69 WSKOW (EPI Suite) 2
25 1.86E-4 -3.73 Mazzoni et al. 2
25 1.45E-4 -3.84 Ahmed et al. 2
25 1.86E-4 -3.73 Varaprath et al. 2

Henry's law constant

t/°C H/Pa m3 mol-1 KAW log (KAW) method and notes reference
25 5.37 0.73 EPI Suite estimation
25 41.7 1.62 COSMOtherm calculation 2
25 15.8 1.2 SPARC estimation 2
25 490 2.69 Mazzoni et al. 2
25 4.79 0.68 Hamelink et al. 2
25 18.2 1.26 Kochetkov et al. 2
25 692 2.84 Xu & Kropscott 2

Octanol-water partition ratio

t/°C KOW log (KOW) method and notes reference
25 6.17E+6 6.79 EPI Suite estimation
25 2.14E+6 6.33 COSMOtherm calculation 2
25 4.57E+6 6.66 SPARC estimation 2
25 1.23E+5 5.09 Mazzoni et al. 2
25 1.26E+7 7.1 Ahmed et al. 2
25 2.82E+4 4.45 Bruggeman et al. 2
25 1.26E+5 5.1 IUCLID 2005 2
25 1.10E+7 7.04 Xu & Kropscott 2

Octanol-air partition ratio

t/°C KOA log (KOA) method and notes reference
25 1.15E+6 6.06 EPI Suite estimation
25 6.46E+4 4.81 COSMOtherm calculation 2
25 3.98E+5 5.6 SPARC estimation 2
25 3.39E+4 4.53 2
25 1.62E+4 4.21 Xu & Kropscott 2
25 2.04E+4 4.31 Xu & Kropscott 2

Half-life for degradation in air

t/°C half-life/day method and notes reference
25 11 EPI Suite estimation
25 4.5 Extrapolated from measured reaction with ·OH 3
25 5.5 Extrapolated from measured reaction with ·OH 4
25 10 Extrapolated from measured reaction with ·OH 5
25 11 Selected as input for global tranport modeling 6

Half-life for degradation in water

t/°C half-life/day method and notes reference
25 38 EPI Suite estimation
25 4.0 Selected as input for global tranport modeling 6

Half-life for degradation in soil

t/°C half-life/day method and notes reference
25 75 EPI Suite estimation
25 5.0 Selected as input for global tranport modeling 6

Half-life for degradation in sediment

t/°C half-life/day method and notes reference
25 338 EPI Suite estimation
25 365 Selected as input for global tranport modeling 6

References

1.
http://www.chemicalbook.com/CASEN_556-67-2.htm
2.
Buser, A.M., Schenker, S., Scheringer, M., Hungerbuehler, K. Journal of Chemical & Engineering Data, 2013, 58, 3170-3178.
3.
Xiao, R., Zammit, I., Wei, Z., Hu, W.P., MacLeod, M., Spinney, R. Environmental Science & Technology 2015, 49, 13322-13330.
4.
Safron, A., Strandell, M., Kierkegaard, A., MacLeod, M. International Journal of Chemical Kinetics 2015, 47, 420-428.
5.
Atkinson, R. Environmental Science & Technology 1991 25, 863-866.
6.
Xu, S., Wania, F. Chemosphere 2013, 93, 835-843.